黑色风格淡入淡出效果多级菜单，这是来自国外网站的一个特效菜单，理论上可以实现无限级，请根据自己的需求修改吧，应用jQuery技术，很不错！-Black style fade effect multi-level menu, this menu is a special effect foreign sites, in theory, can achieve unlimited level, according to their own needs to modify it, use jQuer